A container filled with 12 durians has a mass of 9.27 kg. The same container when filled with 4 mangoes has a mass of 0.91 kg. The mass of 1 durian is four times the mass of 1 mango. Find the mass of the container when it is empty. Express the answer in g.
1 kg = 1000 g

9.27 kg = 9270 g
0.91 kg = 910 g

1 mango = 1 u
4 mangoes = 4 x 1 u = 4 u

1 container + 4 mangoes = 910
1 container + 4 u = 910 --- (1)

1 durian = 4 u
12 durians = 12 x 4 u = 48 u

1 container + 12 durians = 9270
1 container + 48 u = 9270 --- (2)

(2) - (1)
48 u - 4 u = 9270 - 910
44 u = 8360

1 u = 8360 ÷ 44 = 190

4 u = 4 x 190 = 760

From (1):
1 container + 4 u = 910
1 container + 760 = 910
 
1 container = 910 - 760 = 150

Mass of 1 container = 150 g

Answer(s): 150 g